Coupling mechanisms for surgical instruments

ABSTRACT

A surgical instrument includes a shaft defining a longitudinal axis therethrough and having an end effector assembly disposed at a distal end thereof. The shaft includes first and second shaft components that are releasably engageable with one another. A drive sleeve is disposed within the shaft and is longitudinally translatable relative to the shaft to transition the end effector assembly between a first state and a second state. The drive sleeve includes first and second drive sleeve components that are releasably engageable with one another. A coupling mechanism includes one or more shaft cantilever springs configured to releasably engage the first and second shaft components to one another and one or more drive sleeve cantilever springs configured to releasably engage the first and second drive sleeve components to one another.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical instruments and, moreparticularly, to coupling mechanisms for surgical instruments havingseparable and/or replaceable components.

2. Background of Related Art

A forceps is a plier-like instrument which relies on mechanical actionbetween its jaws to grasp, clamp and constrict vessels or tissue.Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to affect hemostasis by heating tissue and bloodvessels to coagulate and/or cauterize tissue. Certain surgicalprocedures require more than simply cauterizing tissue and rely on theunique combination of clamping pressure, precise electrosurgical energycontrol and gap distance (i.e., distance between opposing jaw memberswhen closed about tissue) to “seal” tissue, vessels and certain vascularbundles. Typically, once a vessel is sealed, the surgeon has toaccurately sever the vessel along the newly formed tissue seal.Accordingly, many vessel sealing instruments have been designed whichincorporate a knife or blade member which effectively severs the tissueafter forming a tissue seal.

Generally, surgical instruments, including forceps, can be classified assingle-use instruments, e.g., instruments that are discarded after asingle use, partially-reusable instruments, e.g., instruments includingboth disposable portions and portions that are sterilizable for reuse,and completely reusable instruments, e.g., instruments that arecompletely sterilizable for repeated use. As can be appreciated, thoseinstruments (or components of instruments) that can be sterilized andreused help reduce the costs associated with the particular surgicalprocedure for which they are used. However, although reusable surgicalinstruments are cost-effective, it is important that these instrumentsbe capable of performing the same functions as their disposablecounterparts, that any disposable components of these instruments beefficiently removable and replaceable with new components, and that thereusable components be efficiently and satisfactorily sterilizable forreuse.

SUMMARY

As used herein, the term “distal” refers to the portion that is beingdescribed which is further from a user, while the term “proximal” refersto the portion that is being described which is closer to a user.

Any of the aspects disclosed herein, to the extent they are consistent,may be used in conjunction with any of the other aspects disclosedherein.

In accordance with one aspect of the present disclosure, a surgicalinstrument is provided. The surgical instrument includes a shaftdefining a longitudinal axis therethrough and having an end effectorassembly disposed at a distal end thereof. The shaft includes first andsecond shaft components that are releasably engageable with one another.A drive sleeve is disposed within the shaft and is longitudinallytranslatable relative to the shaft to transition the end effectorassembly between a first state and a second state. The drive sleeve alsoincludes first and second drive sleeve components that are releasablyengageable with one another. A coupling mechanism includes one or moreshaft cantilever springs and one or more drive sleeve cantilever springsthat are coupled to the one or more shaft cantilever springs. The shaftcantilever springs are configured to engage the first shaft component ata first end thereof and the second shaft component at a second endthereof to releasably engage the first and second shaft components toone another. Similarly, the drive sleeve cantilever springs areconfigured to engage the first drive sleeve component at a first endthereof and the second drive sleeve component at a second end thereof toreleasably engage the first and second drive sleeve components to oneanother.

In one aspect, the shaft cantilever springs include a first tab disposedat the first end thereof and extending therefrom and a second tabdisposed at the second end thereof and extending thereform. The firsttab and second tabs are configured to bias into engagement withinapertures defined within the first and second shaft components,respectively, to engage the first and second shaft components to oneanother. Further, the drive sleeve cantilever springs may also include afirst tab disposed at the first end thereof and extending therefrom anda second tab disposed at the second end thereof and extending thereform.The first tab and second tabs are configured to bias into engagementwithin apertures defined within the first and second drive components,respectively, to engage the first and second drive sleeve components toone another.

In another aspect, the shaft cantilever spring and the drive sleevecantilever spring are coupled to one another via a break-away feature.The break-away feature is configured to break, decoupling the shaftcantilever spring and the drive sleeve cantilever spring from oneanother to permit the drive sleeve to translate relative to the shaft.

In still another aspect, a knife assembly is disposed within the drivesleeve. The knife assembly includes a knife bar having a knife disposedat a distal end of the knife bar. The knife bar is longitudinallytranslatable through the shaft and relative to the end effector assemblyto translate the knife between a retracted position and an extendedposition for cutting tissue.

Another aspect of a surgical instrument provided in accordance with thepresent disclosure includes a shaft defining a longitudinal axistherethrough and having an end effector assembly disposed at a distalend thereof. The shaft includes first and second shaft components thatare releasably engageable with one another. The first shaft componentincludes a tab disposed on an outer surface thereof and extendingoutwardly therefrom, while the second shaft component includes a trackdefined within an outer peripheral surface thereof. The track includes alongitudinal portion, a transverse portion, and a tab retaining portion.The first shaft component is configured for insertion at least partiallyinto the second shaft component such that the tab is translated alongthe longitudinal portion of the track into position adjacent thetransverse portion of the track. The first shaft component is thenrotatable about the longitudinal axis and relative to the second shaftcomponent to translate the tab along the transverse portion of the trackand into the tab retaining portion for releasably engaging the first andsecond shaft components to one another.

In one aspect, a biasing member configured to bias the first and secondshaft components apart from one another is provided. The biasing memberbiases the tab into engagement within the tab retaining portion of thetrack to maintain the first and second shaft components in engagementwith one another.

In another aspect, the first and second shaft components are configuredto permit translation of a drive sleeve therethrough for transitioningthe end effector assembly between a first state and a second state.

In yet another aspect, the surgical instrument further includes a knifeassembly disposed within the drive sleeve. The knife assembly includes aknife bar having a knife disposed at a distal end of the knife bar andis longitudinally translatable through the shaft and relative to the endeffector assembly to translate the knife between a retracted positionand an extended position for cutting tissue.

Still another aspect of a surgical instrument provided in accordancewith the present disclosure includes a shaft defining a longitudinalaxis therethrough and having an end effector assembly disposed at adistal end thereof. The shaft includes first and second shaft componentsthat are releasably engageable with one another. The first shaftcomponent includes an insertion portion, while the second shaftcomponent includes a receiving portion configured to receive theinsertion portion of the first shaft component therein to frictionallyengage the first and second shaft components to one another. Thereceiving portion is configured to constrict about the insertion portionupon translation of the insertion portion apart from the receivingportion to inhibit withdrawal of the insertion portion, therebymaintaining the engagement between the first and second shaftcomponents.

In one aspect, receiving portion defines a braided configurationconfigured to elongate and reduce a diameter of a lumen extendingtherethrough upon extension of the receiving portion.

In another aspect, the insertion portion defines a textured outerperipheral surface configured to facilitate frictional engagementbetween the insertion portion and the receiving portion.

In still another aspect, a release ring is provided. The release ring isdisposed about the first shaft component and is slidable about the firstshaft component into position adjacent the receiving portion of thesecond shaft component to inhibit constriction of the receiving portionabout the insertion portion, thereby permitting withdrawal of theinsertion portion from the receiving portion to disengage the first andsecond shaft components from one another. The surgical instrument mayfurther be configured similar to any of the previous aspects mentionedhereinabove.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described herein withreference to the drawings wherein like reference numerals identifysimilar or identical elements:

FIG. 1 is a side, perspective view of one embodiment of a surgicalinstrument provided in accordance with the present disclosure whereinthe shaft of the instrument is in an assembled condition;

FIG. 2A is a longitudinal, cross-sectional view of the surgicalinstrument of FIG. 1 wherein an end effector assembly is disposed in aspaced-apart position;

FIG. 2B is a longitudinal, cross-sectional view of the surgicalinstrument of FIG. 1 wherein the end effector assembly is disposed in anapproximated position and wherein a knife blade is disposed in aretracted position;

FIG. 2C is a longitudinal, cross-sectional view of the surgicalinstrument of FIG. 1 wherein the end effector assembly is disposed in anapproximated position and wherein the knife blade is disposed in anextended position;

FIG. 3 is an enlarged, side view of a distal end of the surgicalinstrument of FIG. 1, wherein the shaft of the instrument is in adecoupled condition;

FIG. 4 is a transverse, cross-sectional view of the surgical instrumentof FIG. 3 taken across section line 4-4;

FIG. 5A is a side, cross-sectional view of one embodiment of a shaftcoupling mechanism provided in accordance with the present disclosurewherein the shaft is in a decoupled condition;

FIG. 5B is a side, cross-sectional view of the shaft coupling mechanismof FIG. 5A wherein the shaft is in an assembled condition;

FIG. 6A is a side, cross-sectional view of another embodiment of a shaftcoupling mechanism provided in accordance with the present disclosurewherein the shaft is in a decoupled condition;

FIG. 6B is a side, cross-sectional view of the shaft coupling mechanismof FIG. 6A during assembly of the shaft;

FIG. 6C is a side, cross-sectional view of the shaft coupling mechanismof FIG. 6A, wherein the shaft is in an assembled condition;

FIG. 6D is a top view of one of the shaft components of the shaft ofFIG. 6A;

FIG. 6E is a transverse, cross-sectional view taken along section line6E-6E of FIG. 6C;

FIG. 7A is a side view of still another embodiment of a shaft couplingmechanism provided in accordance with the present disclosure wherein theshaft is in a decoupled condition;

FIG. 7B is a side view of the shaft coupling mechanism of FIG. 7Awherein the shaft is in an assembled condition;

FIG. 8 is a side, perspective view of yet another embodiment of a shaftcoupling mechanism provided in accordance with the present disclosurewherein the shaft is in a decoupled condition;

FIG. 9 is a side view of still yet another embodiment of a shaftcoupling mechanism provided in accordance with the present disclosurewherein the shaft is in a decoupled condition;

FIG. 10 is a side view of another embodiment of a shaft couplingmechanism provided in accordance with the present disclosure wherein theshaft is in a decoupled condition;

FIG. 11 is a side view of another embodiment of a shaft couplingmechanism provided in accordance with the present disclosure wherein theshaft is in a decoupled condition;

FIG. 12 is a side view of another embodiment of a shaft couplingmechanism provided in accordance with the present disclosure wherein theshaft is in a decoupled condition;

FIG. 13 is a side, cross-sectional view of still another embodiment of ashaft coupling mechanism provided in accordance with the presentdisclosure wherein the shaft is in a decoupled condition;

FIG. 14 is a side view of yet another embodiment of a shaft couplingmechanism provided in accordance with the present disclosure wherein theshaft is in a decoupled condition; and

FIG. 15 is a side view of still yet another embodiment of a shaftcoupling mechanism provided in accordance with the present disclosurewherein the shaft is in a decoupled condition.

DETAILED DESCRIPTION

Referring now to FIG. 1, a forceps 10 for use in connection withendoscopic surgical procedures is shown, although forceps 10 may also beconfigured for use in connection with traditional open surgicalprocedures. Forceps 10 defines a longitudinal axis “A-A” and includes ahousing 20, a handle assembly 30, a trigger assembly 70, a rotatingassembly 80, and an end effector assembly 100. End effector assembly 100includes first and second jaw members 110, 120, respectively, configuredto pivot relative to one another between a spaced-apart position(FIG. 1) and an approximated position (FIG. 8B) for grasping tissuetherebetween. Forceps 10 further includes a shaft 12 having a distal end14 configured to mechanically engage end effector assembly 100 and aproximal end 16 that mechanically engages housing 20.

Forceps 10 also includes an electrosurgical cable 310 that connectsforceps 10 to a generator (not shown) or other suitable power source,although forceps 10 may alternatively be configured as a battery poweredinstrument. Cable 310 includes a wire (or wires) (not explicitly shown)extending therethrough, into housing 20 and through shaft 12 toultimately connect the source of electrosurgical energy (not explicitlyshown) to jaw member 110 and/or jaw member 120 of end effector assembly100. However, any other suitable electrical connection(s) for supplyingenergy to jaw member 110 and/or jaw member 120 may also be provided.

With continued reference to FIG. 1, handle assembly 30 includes a fixedhandle 50 and a moveable handle 40. Fixed handle 50 is integrallyassociated with housing 20 and handle 40 is moveable relative to fixedhandle 50. Rotating assembly 80 is rotatable in either direction about alongitudinal axis “A-A” to rotate end effector 100 about longitudinalaxis “A-A.” The housing 20 houses the internal working components of theforceps 10.

End effector assembly 100 is attached at a distal end 14 of shaft 12 andincludes a pair of opposing jaw members 110 and 120. End effectorassembly 100 is designed as a unilateral assembly, i.e., where jawmember 120 is fixed relative to shaft 12 and jaw member 110 is moveablerelative to both shaft 12 and fixed jaw member 120. However, endeffector assembly 100 may alternatively be configured as a bilateralassembly, i.e., where both jaw member 110 and jaw member 120 aremoveable relative to one another and with respect to shaft 12.

As shown in FIG. 1, each jaw member 110, 120 includes an electricallyconductive tissue sealing plate 112, 122 disposed thereon. Tissuesealing plates 112, 122 are positioned on jaw members 110, 120,respectively, to define opposed tissue sealing surfaces for grasping andsealing tissue between jaw members 110, 120. In some embodiments, aknife assembly 180 (see FIGS. 2A-2C) is disposed within shaft 12 and aknife channel 115, 125 (FIGS. 2A-2C) is defined within one or both oftissue sealing plates 112, 122, of jaw members 110, 120, respectively,to permit reciprocation of a knife 184 (see FIGS. 2A-2C) therethroughfor cutting tissue grasped between jaw members 110, 120. In such anembodiment, trigger 72 of trigger assembly 70 is operable to advance theknife 184 (FIGS. 2A-2C) between a retracted position (see FIGS. 2A-2B),wherein knife 184 (FIGS. 2A-2C) is disposed within shaft 12, and anextended position (see FIG. 2C), wherein knife 184 (FIGS. 2A-2C) extendsbetween jaw members 110, 120 to cut tissue grasped therebetween.

Continuing with reference to FIG. 1, moveable handle 40 of handleassembly 30 is ultimately connected to a drive assembly including adrive sleeve 60 (FIG. 4) that, together, mechanically cooperate toimpart movement of jaw members 110 and 120 between a spaced-apartposition and an approximated position to grasp tissue between sealingplates 112 and 122 of jaw members 110, 120, respectively. As shown inFIG. 1, moveable handle 40 is initially spaced-apart from fixed handle50 and, correspondingly, jaw members 110, 120 are disposed in thespaced-apart position. Moveable handle 40 is depressible from thisinitial position to a depressed position corresponding to theapproximated position of jaw members 110, 120 (see FIGS. 2B-2C). Withtissue grasped between tissue sealing plates 112, 122 of jaw members110, 120, respectively, electrosurgical energy may be conducted betweentissue sealing plates 112, 122, e.g., upon actuation of activationswitch 90, to seal tissue disposed between jaw members 110, 120.

With reference now to FIGS. 2A-2C, in conjunction with FIG. 1, drivesleeve 60 is disposed within shaft 12 and is coupled to jaw member 110at the distal end thereof such that, as drive sleeve 60 is translatedproximally through shaft 12 and relative to jaw member 120, e.g., viadepressing movable handle 40, jaw member 110 is pulled to pivot from thespaced-apart position (FIG. 2A) to the approximated position (FIGS. 2B,2C). On the other hand, when drive sleeve 60 is translated distally,e.g., via releasing or returning movable handle 40 to its initialposition, jaw member 110 is urged to pivot from the approximatedposition (FIGS. 2B, 2C) back to the spaced-apart position (FIG. 2A).However, this configuration may be reversed, e.g., where proximaltranslation of drive sleeve 60 moves jaw members 110, 120 to thespaced-apart position and wherein distal translation of drive sleeve 60moves jaw members 110, 120 to the approximated position.

Continuing with reference to FIGS. 2A-2C, shaft 12 further includes aknife assembly 180 disposed therein. Knife assembly 180 is disposedwithin drive sleeve 60 and includes a knife bar 182 having knife 184coupled thereto at the proximal end of 185 of knife 184. Knife 184defines a cutting blade 186 at distal end 187 thereof. Knife 184 istranslatable between a retracted position (FIGS. 2A-2B), wherein knife184 is disposed within shaft 12, and an extended position (FIG. 2C),wherein knife 184 extends through knife channels 115, 125 defined withinjaw members 110, 120, respectively, to cut tissue grasped between jawmembers 110, 120. More specifically, upon actuation of trigger 72(FIG. 1) of trigger assembly 70 (FIG. 1), knife bar 182 is advanceddistally through shaft 12 and drive sleeve 60 to urge knife 184 from theretracted position to the extended position. Further, knife assembly 180may be biased, e.g., via a spring (not explicitly shown), toward theretracted position such that, upon release of trigger 72, knife 184 isautomatically returned to the retracted position.

Turning now to FIGS. 3-4, in conjunction with FIGS. 1-2C, shaft 12 offorceps 10 is separable, or decouplable into first and second shaftsections 17 and 18, respectively. More specifically, second section 18of shaft 12, including end effector assembly 100, is removable from theremainder of forceps 10, thus allowing second section 18 of shaft 12 andend effector assembly 100 to be replaced with new components after eachuse (or each procedure), or to be cleaned, sterilized, or otherwiseprepared for reuse independently of the remaining components of forceps10. Such a configuration also permits the use of various different endeffector assemblies with forceps 10 by simply selecting the desired endeffector assembly and coupling that end effector assembly and the secondshaft section 18 thereof to first section 17 of shaft 12.

Put more generally, the replaceable distal portion, e.g., second shaftsection 18 and end effector assembly 100, of forceps 10 helps reduce theequipment costs associated with performing a particular surgicalprocedure by obviating the need to provide an entire new surgicalinstrument, facilities sterilization and cleaning of the components ofthe instrument by providing greater access to the components of theinstrument and allowing different components of the instrument to becleaned and/or sterilized via different procedures, and increases theversatility of the instrument by allowing different shaft componentsand/or end effectors to be coupled thereto.

However, while it is advantageous to provide a surgical instrument,e.g., forceps 10, that includes a shaft 12 that is separable into firstand shaft sections 17 and 18, respectively, significant considerationsapply when configuring a shaft coupling mechanism for releasablycoupling first and second shaft sections 17, 18, respectively, to oneanother. In particular, it is important to consider the variouscomponents and connections extending through shaft 12. Morespecifically, as best shown in FIG. 4, shaft 12 defines an outer tube,or lumen that houses drive sleeve 60. Drive sleeve 60, as mentionedabove, is selectively translatable through and relative to shaft 12 topivot jaw member 110 relative to jaw member 120 between the spaced-apartand approximated positions. Drive sleeve 60 also includes knife bar 182disposed therein that, as described above, is selectively translatablerelative to drive sleeve 60 and shaft 12 to advance knife 184 from theretracted position to the extended position to cut tissue graspedbetween jaw members 110, 120. Further, electrical connections, e.g.,wires (not explicitly shown), extend through shaft 12 to connect thesource of electrosurgical energy (not explicitly shown) to jaw member110 and/or jaw member 120 of end effector assembly 100 for providingenergizing end effector assembly.

Various embodiment of coupling mechanisms configured to releasablycouple the first and second sections 17 and 18, respectively, of shaft12 to one another in accordance with those considerations addressedabove will be described in detail below with reference to FIGS. 5A-15.More particularly, the coupling mechanisms described hereinbelow may beconfigured for coupling the first and second sections 17, 18 of shaft12, the components of drive sleeve 60, and/or the components of knifebar 182 to one another, as well as for re-establishing and electricalconnections extending through shaft 12. Further, the various couplingmechanisms described hereinbelow may be used alone or in combinationwith one another to releasably couple one or more of the respectivecomponents of shaft 12, drive sleeve 60, and/or knife bar 182 to oneanother. Thus, while certain coupling mechanisms may be shown anddescribed with reference to only a single connection, e.g., for couplingthe first and second sections 17, 18 of shaft 12 to one another, suchmechanisms (or other coupling mechanisms) may also be used for furthercoupling the other components, e.g., first and second sections of thedrive sleeve 60 and/or knife bar 182, to one another. Likewise, theelectrical connections described hereinbelow in connection with someembodiments of coupling mechanisms for electrically coupling the firstand second sections 17, 18, respectively, of shaft 12 to one anothersuch that electrosurgical energy may be supplied from housing 20 to endeffector assembly 100 may also be used in conjunction with any of theother coupling mechanisms described herein.

Additionally, although the embodiments herein are described withreference to a forceps 10, the presently disclosed coupling mechanismsmay be used in conjunction with any shafted surgical instrument(including single or multiple component shafts) having an end effectorassembly disposed at one end and a handle, housing, grip, control, etc.disposed at the other end. Further, the attachment point of first andsecond sections 17, 18, respectively, of shaft 12 may be disposed atvarious positions along the length of shaft 12, e.g., closer towardsdistal end 14 such that second section 18 defines a greater length thanfirst portion 17, closer toward proximal end 16 such that first section17 defines a greater length than first portion 17, or anywhere betweenproximal end 16 and distal end 14 of shaft 12.

Referring now to FIGS. 5A-5B, one embodiment of a tube couplingmechanism for coupling first and second components 517, 518,respectively, of shaft 512 to one another as well as for coupling firstand second components 567, 568, respectively, of drive sleeve 560 to oneanother is shown generally identified by reference numeral 500. Tubecoupling mechanism 500 includes two sets of cantilever springs 520, 530and 570, 580. Each cantilever spring 520, 530 of the first set includesan arm 522, 532 that has a first tab 524, 534 disposed at a first end525, 535, respectively, thereof and a second tab 526, 536 disposed atsecond end 527, 537, respectively, thereof. First tabs 524, 534 areengaged within apertures 542, 544, respectively, of second component 518of shaft 512, while second tabs 526, 536 are configured for engagementwithin apertures 546, 548, respectively, defined within first component517 of shaft 512. More specifically, as will be described below,cantilever springs 520, 530 are configured to resiliently bias secondtabs 526, 536, respectively, into engagement with respective apertures546, 548 of first component 517 upon insertion into shaft 512 to engagefirst and second components 517, 518, respectively, of shaft 512 to oneanother.

Each cantilever spring 570, 580 of the second set similarly includes anarm 572, 582 that has a first tab 574, 584 disposed at a first end 575,585, respectively, thereof and a second tab 576, 586 disposed at secondend 577, 587, respectively, thereof. First tabs 574, 584 are engagedwithin apertures 592, 594, respectively, of second component 568 ofdrive sleeve 560, while cantilever springs 570, 580 are configured toresiliently bias second tabs 576, 586, respectively, into engagementwith respective apertures 566, 568 of first component 567 of drivesleeve 560 upon positioning about drive sleeve 560 to engage first andsecond components 567, 568, respectively, of drive sleeve 560 to oneanother. Further, cantilever springs 520, 570 may be coupled, engaged,or otherwise formed to one another adjacent first end 525 of cantileverspring 520 and second end 577 of cantilever spring 570 via a break-awayfeature, or coupling 549. Cantilever springs 530, 580 may likewise becoupled, engaged, or otherwise formed to one another adjacent first end535 of cantilever spring 530 and second end 587 of cantilever spring 580via a break-away feature, or coupling 599.

With continued reference to FIGS. 5A-5B, in order to couple first andsecond components 517, 518, respectively, of shaft 512 to one anotherand first and second components 567, 568, respectively, of drive sleeve560 to one another, first and second component 517, 518 of shaft 512 arebrought into approximation with one another. As can be appreciated,approximation of first and second component 517, 518 of shaft 512likewise approximates first and second components 567, 568 of drivesleeve 560 due to the engagement of cantilever springs 520, 570 and 530,580 via break-away couplings 549, 599, respectively. More specifically,as first and second component 517, 518 of shaft 512 are brought intoapproximation with one another, second tabs 526, 536 of cantileversprings 520, 530, respectively, are flexed inwardly, i.e., toward oneanother, to permit passage of cantilever springs 520, 530 into lumen 514defined through shaft 512. On the other hand, second tabs 576, 586 ofcantilever springs 570, 580, respectively, are flexed outwardly, i.e.,apart from one another, to permit passage of cantilever springs 570, 580about drive sleeve 560.

As first and second components 517, 518 of shaft 512 are furtherapproximated relative to one another, second tabs 526, 536 of cantileversprings 520, 530, respectively, are eventually translated through lumen514 of shaft 512 into position adjacent apertures 542, 544 of firstcomponent 517, whereby cantilever springs 520, 530 are resilientlybiased back to their initial, un-flexed position, thus urging secondtabs 526, 536 into engagement within apertures 542, 544, respectively,to engage first and second components 517, 518, respectively, of shaft512 to one another. Similarly, second tabs 576, 586 of cantileversprings 570, 580, respectively, are eventually translated about theouter periphery of first component 567 of drive sleeve 560 into positionadjacent apertures 592, 594 of first component 567, whereby cantileversprings 570, 580 are resiliently biased back to their initial, un-flexedposition, thus urging second tabs 576, 586 into engagement withinapertures 592, 594, respectively, to engage first and second components567, 568, respectively, of drive sleeve 560 to one another.

With first and second components 517, 518 of shaft 512 engaged to oneanother and with first and second components 567, 568 of drive sleeve560 engaged to one another, drive sleeve 560 may be translated relativeto shaft 512 an initial time, e.g., via depressing movable handle 40(FIG. 1), to break, tear, or otherwise destroy break-away couplings 549and 599. As can be appreciated, with break-away couplings 549, 599 nolonger securing cantilever springs 520, 270 to one another norcantilever springs 530, 580 to one another, drive sleeve 560 is free totranslate through lumen 514 and relative to shaft 512 for moving jawmembers 110, 120 (FIG. 1) between the spaced-apart and approximatedpositions.

In order to decouple shaft components 517, 518 from one another, a tool(not shown) or other implement may be used to urge tabs 526, 536inwardly such that tabs 526, 536 are no longer disposed within apertures546, 548, respectively. With tabs 526, 536 removed from apertures 546,548, shaft components 517, 518 may be translated apart from one anotherto decouple shaft component 517, 518 from one another. First and secondcomponents 567, 568 of drive sleeve 560 may similarly be decoupled fromone another.

Turning now to FIGS. 6A-6E, another embodiment of a tube couplingmechanism is shown generally identified via reference numeral 600. Tubecoupling mechanism 600 is configured to releasably engage first andsecond components 617, 618 of shaft 612 to one another. Morespecifically, tube coupling mechanism 600 includes a pair of resilientlocking tabs 620, 630 formed in the outer periphery of second component618 and extending outwardly therefrom (although locking tabs 620, 630may alternatively be formed on shaft component 617 to extend inwardlytherefrom). As best shown in FIG. 6A, in an at-rest position, lockingtabs 620, 630 are bent, or folded-back onto themselves and protrude fromthe outer periphery of second shaft component 618. Each locking tab 620,630 defines a free end 622, 632, respectively, that permits resilientflexion of locking tabs 620, 630 relative to second shaft component 618.First shaft component 617, on the other hand, includes a pair ofapertures 640, 650 configured to receive locking tabs 620, 630,respectively, therein. Further, first shaft component 617 may define aslightly larger diameter than second shaft component 618 such thatsecond shaft component 618 may be inserted at least partially into lumen614 of first shaft component 617 to couple first and second shaftcomponents 617, 618, respectively, to one another, as will be describedbelow.

With continued reference to FIGS. 6A-6E, in order to engage first andsecond shaft components 617, 618, respectively, to one another, secondshaft component 618 is inserted into lumen 614 defined through firstshaft component 617. As second shaft component 618 is urged into lumen614 of first shaft component 617, resilient locking tabs 620, 630 areflexed, or compressed inwardly into second shaft component 618 in orderto permit passage of second shaft component 618 into lumen 614 of firstshaft component 617, as best shown in FIG. 6B.

As second shaft component 618 is translated further through lumen 614 offirst shaft components 617 tabs 620, 630 are eventually translated intoposition adjacent apertures 640, 650 of first shaft component 617,whereby tabs 620, 630 are resiliently biased back to their initial,un-compressed position (extending from second shaft component 618). Thatis, tabs 620, 630 are urged under bias into engagement within apertures640, 650, respectively, to engage first and second components 617, 618,respectively, of shaft 612 to one another. Similarly as described above,in order to decouple shaft components 617, 618 from one another, a tool(not shown) or other implement may be used to urge tabs 620, 630inwardly such that tabs 620, 630 are no longer disposed within apertures640, 650, respectively. With tabs 620, 630 removed from apertures 640,650, second shaft component 618 may be removed from lumen 614 of firstshaft component 617 to decouple shaft component 617, 618 from oneanother.

Turning now to FIGS. 7A-7B, another embodiment of a tube couplingmechanism is shown generally identified by reference numeral 700. Tubecoupling mechanism 700 is configured to engage first and second shaftcomponent 717, 718, respectively, of shaft 712 to one another. One ofthe shaft components, e.g., first shaft component 717, includes aninsertion portion 720 extending from end 722 thereof, while the othershaft component, e.g., second shaft component 718, includes a receivingportion 730 disposed at end 732 thereof. Insertion portion 720 isconfigured for insertion into lumen 734 of receiving portion 730 forsecuring first and second shaft components 717, 718, respectively, toone another.

As shown in FIG. 7A, insertion portion 720 of first shaft component 717defines a diameter that is smaller relative to the diameter of receivingportion 730 of shaft component 718, such that insertion portion 720 maybe inserted into lumen 734 of receiving portion 730 until ends 722, 732of first and second shaft components 717, 718, respectively, areabutting one another, as shown in FIG. 7B. Thereafter, insertion portion720 and/or receiving portion 730 are transitioned from this firstcondition, wherein the diameter of insertion portion 720 is smaller thanthe diameter of receiving portion 730, to a second, or engagedcondition, wherein insertion portion 720 is retained in engagementwithin receiving portion 730 via friction-fitting. As can beappreciated, in the engaged condition, the diameters of insertionportion 720 and receiving portion 730 may be substantially similar toone another to retain first and second shaft components 717, 718,respectively, in engagement with one another.

In order to engage insertion portion 720 and receiving portion 730 toone another, one or both of the portions 720, 730 are heated, orotherwise treated to achieve the first condition; insertion portion 720in inserted into receiving portion 730; and, finally, insertion portion720 and/or receiving portion 730 are transitioned to the engagedcondition to engage first and second shaft components 717, 718,respectively, to one another. For example, receiving portion 730 ofsecond shaft component 718 may be heated to an expanded state (i.e., thefirst condition) such that insertion portion 720 of first shaftcomponent 717 may be inserted into lumen 734 of receiving portion 730.Thereafter, receiving portion 730 is cooled, or allowed to cool, suchthat receiving portion 730 is contracted about insertion portion 720back to its initial condition to engage insertion portion 720 therein.

Alternatively, insertion portion 720 and receiving portion 730 may beformed from materials having different coefficients of expansion suchthat both insertion portion 720 and receiving portion 730 may be heatedto permit insertion portion 720 to be inserted into receiving portion730. Thereafter, both insertion portion 720 and receiving portion 730are allowed to cool, or are cooled, back to their initial states toengage insertion portion 720 within receiving portion 730. Insertionportion 720 and/or receiving portion 730 may also be formed form shapememory materials, or may include thermal or electric bimetal materialsdisposed thereon to facilitate transitioning of insertion portion 720and receiving portion 730 between the first and second conditions forsecuring first and second shaft components 717, 718, respectively, toone another.

In order to decouple first and second shaft components 717, 718,respectively, from one another, one or both of insertion portion 720 andreceiving portion 730 are transitioned, e.g., heated, to once againachieve the first condition, thus allowing first and second shaftcomponents 717, 718 to be translated apart from one another such thatinsertion portion 720 is removed from lumen 734 of receiving portion730.

FIG. 8 shows another embodiment of a shaft coupling mechanism 800 thatis configured to releasably engage first and second shaft components817, 818, respectively, of shaft 812 to one another. Shaft couplingmechanism 800 generally includes a tab 820 disposed on and extendingfrom an outer periphery of one of the shaft components, e.g., secondshaft component 818, and a slot 830 defined within the outer peripheryof the other shaft component, e.g., first shaft component 817. Slot 830includes a longitudinal segment 836 having an open distal end 837 atdistal end 832 of first shaft component 817 and a locking segment 840 incommunication with longitudinal segment 836 at proximal end 838 thereof.Locking segment 840 includes a transverse portion 842 extending insubstantially-transverse relation relative to longitudinal segment 836,and a distally-extending tab-retaining portion 844 in communicationtherewith. First shaft component 817 further includes a biasing member,e.g., a spring 848 disposed within lumen 834 thereof, the importance ofwhich will be described below.

With continued reference to FIG. 8, second shaft component 818 defines adiameter smaller than that of first shaft component 817 to permitpassage of second shaft component 818 into lumen 834 of first shaftcomponent 817. Further, tab 820 of second shaft component 818 isconfigured to be received within, and to translate through slot 830 offirst shaft component 817 to engage first and second shaft components817, 818, respectively, to one another.

In order to engage first and second shaft components 817, 818,respectively, to one another, second shaft component 818 is insertedinto lumen 834 of first shaft component 817 such that tab 820 isinserted into longitudinal segment 836 of slot 830 via open distal end837 thereof. As second shaft component 818 is translated further intolumen 834 of first shaft component 817, tab 820 is translated proximallyalong longitudinal segment 836 of slot 830 towards proximal end 838thereof. However, prior to tab 820 reaching proximal end 838 oflongitudinal segment 836 of slot 830, proximal end 822 of second shaftcomponent 818 contacts biasing member 848. As such, in order totranslate second shaft component 818 further through lumen 834 of firstshaft component 817, second shaft component 818 must be urgedsufficiently to overcome the bias of biasing member 848.

Eventually, second shaft component 818 is translated proximally, againstthe bias of biasing member 848, such that tab 820 is disposed atproximal end 838 of longitudinal segment 836 of slot 830. Once thisposition is achieved, second shaft component 818 is rotated aboutlongitudinal axis “A-A” relative to first shaft component 817 such thattab 820 is translated along transverse portion 842 of locking segment840 into position adjacent tab-retaining portion 844 of locking segment840 of slot 830. Thereafter, second shaft component 818 may be released,allowing biasing member 848 to bias second shaft component 818 distallysuch that tab 820 is translated distally into tab-retaining portion 844of locking segment 840 of slot 830 to engage first and second shaftcomponents 817, 818, respectively, to one another.

In order to disengage first and second shaft components 817, 818,respectively, from one another, second shaft component 818 is translatedproximally relative to first shaft component 817 such that tab 820 istranslated proximally from tab-retaining portion 844 of locking segment840 into transverse portion 842 of locking segment 840 of slot 830.Thereafter, second shaft component 818 is rotated relative to firstshaft component 817 about longitudinal axis “A-A” such that tab 820 isonce again aligned with longitudinal segment 836 of slot 830 so thatsecond shaft component 818 can be translated distally and removed fromfirst shaft component 817, thereby decoupling first and second shaftcomponents 817, 818, respectively, from one another.

Referring now to FIG. 9, shaft coupling mechanism 900 is configured toengage first and second shaft components 917, 918, respectively, ofshaft 912 to one another. Shaft coupling mechanism 900 includes a firsthub 920 disposed on one of the shaft components, e.g., first shaftcomponent 917, and a second hub 930 disposed on the other shaftcomponent, e.g., second shaft component 918. More specifically, firsthub 920 extends from distal end 922 of first shaft component 917 anddefines a reduced diameter relative to first shaft component 917 suchthat a distally-facing shoulder 924 is defined therebetween. Further,first hub 920 includes a helical track 926 defined within an outerperiphery thereof, the helical track 926 including an open distal end927 and a retaining notch 928 formed at proximal end 929 thereof. AnO-ring 940, or other suitable resilient biasing member, is disposedabout first hub 920 adjacent shoulder 924.

Second hub 930 extends from proximal end 932 of second shaft component918 and defines a lumen 934 extending therethrough that is configured toreceive first hub 920 of first shaft component 917 therein. Second hub930 further includes a tab 936 disposed on an inner surface thereof andextending inwardly into lumen 934. Tab 936 is configured to be receivedwithin, and to translate through track 926 of first hub 920.

In use, to couple first and second shaft components 917, 918,respectively, to one another, first and second shaft components 917, 918are translated toward one another until first hub 920 extends partiallyinto second hub 930 such that tab 936 enters open distal end 927 oftrack 926. With tab 936 positioned within track 926, second shaftcomponent 918 is rotated relative to first shaft component 917 aboutlongitudinal axis “A-A” such that tab 936 is translated proximallythrough track 926, thereby further engaging first hub 920 within secondhub 930. Upon further rotation of second shaft component 918 relative tofirst shaft component 917 and, thus, upon further translation of firsthub 920 into second hub 930, tab 936 is translated through track 926into position adjacent retaining notch 928 of track 926. However, inthis position, second hub 930 is positioned adjacent O-ring 940. Thus,in order to translate tab 936 into notch 928, second shaft component 918is rotated with sufficient urging to compress O-ring 940, thuspermitting further proximal translation of tab 936 through helical track926. Ultimately, once tab 936 has reached notch 928, second shaftcomponent 918 may be released, allowing O-ring 940 to resiliently returnto its at rest condition such that second shaft component 918 is biaseddistally and, thus, tab 936 is biased into engagement within notch 928to engage first and second shaft components 917, 918, respectively, toone another.

In order to decouple first and second shaft components 917, 918,respectively, from one another, second shaft component 918 is translatedproximally relative to first shaft component 917 such that second shaftcomponent 918 is urged against first O-ring 940 to compress O-ring 940,allowing second shaft component 918 to translate further proximally. Inthis position, tab 936 of second shaft component 918 is once againaligned with helical track 926 such that second shaft component 918 maybe rotated about longitudinal axis “A-A” to translate tab 936 distallythrough helical track 926, ultimately disengaging first and second shaftcomponents 917, 918, respectively, from one another.

FIG. 10 shows another embodiment of a shaft coupling mechanism 1000configured for releasably engaging first and second shaft components1017, 1018, respectively, of shaft 1012 to one another. Shaft couplingmechanism 1000 includes a first hub 1020 disposed on one of the shaftcomponents, e.g., first shaft component 1017, and a second hub 1030disposed on the other shaft component, e.g., second shaft component1018. Shaft coupling mechanism 1000 further includes a sleeve 1050slidably disposed about shaft 1012, the importance of which will bedescribe below.

First hub 1020 of shaft coupling mechanism 1000 extends from distal end1022 of first shaft component 1017 and defines a pair of opposed notches1024 within the outer periphery thereof. Alternatively, rather thannotches 1024, an annular groove (not shown) may be defined therein. AnO-ring 1040, or other suitable biasing member is disposed about firstshaft component 1017 and is disposed within each of notches 1024.

Second hub 1030 extends from proximal end 1032 of second shaft component1018 and defines a lumen 1034 extending therethrough that is configuredto receive first hub 1020 of first shaft component 1017 therein. Secondhub 1030 further includes a pair of opposed cantilever springs 1036extending proximally therefrom. Each of the cantilever springs 1036defines a tab 1038 at a free end thereof. Tabs 1038 extend inwardlytoward one another and are configured for engagement within notches 1024of first hub 1020. Alternatively, rather than a pair of opposedcantilever spring 1036, second hub 1030 may include an annular biasingmember (not shown) configured for engagement within an annular groove(not shown) defined within first hub 1020.

First and second hubs 1020, 1030 may each further include complementaryelectrical connection members 1060, 1070, respectively. Morespecifically, one of the first and second hubs, e.g., first hub 1020,may include a female connection member 1060, while the other hub, e.g.,second hub 1030, includes a male connection member 1070 configured forinsertion into female connection member 1060 to electrically couplefirst and second shaft components 1017, 1018, respectively, to oneanother, thus permitting energy to be supplied from the energy source(not explicitly shown) to end effector assembly 100 (FIG. 1).

In order to engage first and second components 1017, 1018, respectively,of shaft 1012 to one another, first and second component 1017, 1018 ofshaft 1012 are brought into approximation with one another. As first andsecond components 1017, 1018 of shaft 1012 are brought intoapproximation with one another, tabs 1038 of cantilever springs 1036 areflexed outwardly, i.e., apart from one another, to permit passage firsthub 1020 into lumen 1034 of second hub 1030.

As first hub 1020 is inserted further into lumen 1034 of second hub1030, tabs 1038 are translated proximally along the outer periphery offirst hub 1020. Eventually, tabs 1030 are translated into positionadjacent notches 1024 defined within first hub 1020. Once disposedadjacent notches 1024, the resilient biasing force of cantilever springs1036 urges tabs 1038 inwardly back toward their initial position suchthat tabs 1038 are engaged within notches 1024, thereby engaging firstand second shaft components 1017, 1718 to one another. O-ring 1040,which is also disposed within notches 1024, biases tabs 1038 intofrictional engagement within notches 1024, ensuring sufficientlyengagement therebetween. Translation of first hub 1020 further intolumen 1034 of second hub 1030 also translates male connection member1070 into engagement with female connection member 1060 to electricallycouple first and second shaft components 1017, 1018, respectively, toone another.

With first and second shaft components 1017, 1018, respectively, engagedto one another, sleeve 1050 may be slid distally about shaft 1012 tosubstantially surround first and second hubs 1020, 1030, respectively.As can be appreciated, with sleeve 1050 disposed about first and secondhubs 1020, 1030, sleeve 1050 helps maintain the engagement between firstand second shaft components 1017, 1018, respectively.

In order to disengage first and second shaft components 1017, 1018,sleeve 1050 is first slid proximally (or distally) such that sleeve 1050is no longer disposed about first and second hubs 1020, 1030,respectively. Thereafter, tabs 1038 are disengaged from notches 1024 andfirst and second shaft components 1017, 1018 are translated apart fromone another, thus disengaging first and second shaft components 1017,1018 from one another.

FIG. 11 shows another embodiment of a tube coupling mechanism 1100configured to releasably engage first and second components 1117, 1118of shaft 1112 to one another. Shaft components 1117, 1118 each include alumen 1122, 1124 extending therethrough. More specifically, lumens 1122,1124 are configured to cooperate with one another to permitreciprocation of drive sleeve 60 (FIGS. 2A-2C) and/or knife bar 182(FIGS. 2A-2C) therethrough to facilitate moving jaw members 110, 120(FIGS. 2A-2C) between the spaced-apart position and the approximatedposition and for translating knife 184 (FIGS. 2A-2C) between theretracted position and the extend position, respectively.

With continued reference to FIG. 11, one of the shaft components, e.g.,first shaft component 1117, includes a pair of pins 1020 extendingdistally therefrom, while the other shaft components, e.g., second shaftcomponent 118 includes a pair of apertures 1130 defined therethrough.Pins 1020 and apertures 1030 are radially-spaced from lumens 1122, 1124,respectively, so as not to interfere with the internal components ofshaft 1112. Pins 1020 are configured to be inserted into apertures 1030to secure first and second shaft components to one another. Morespecifically, pins 1020 define a substantially similar, or slightlysmaller, diameter than that of apertures 1030 to facilitatefriction-fitting engagement between first and second shaft components1117, 1118, respectively. Further, pins 1020 may include a resilientmaterial disposed on the outer periphery thereof (or may be formed froma resilient material or structure), and/or apertures 1030 may alsoinclude a resilient material disposed on the internal surface thereof.In such an embodiment, pins 1020 and/or apertures 1030 are configured tobe compressed upon insertion of pins 1030 and/or apertures 1030 toresiliently bias first and second shaft components 1117, 1118 to oneanother.

Turning now to FIG. 12, yet another embodiment of a tube couplingmechanism configured for engaging first and second shaft components1217, 1218, respectively, of shaft 1212 to one another is showngenerally identified by reference numeral 1200. One of the shaftcomponents, e.g., first shaft component 1217, includes a male connectionmember 1220 extending distally from distal end 1222 therefrom, while theother shaft component, e.g., second shaft component 1218, includes arecess, or female connection member 1230 defined therein at proximal end1232 thereof. Male connection member 1220 and/or female connectionmember 1230 are shaped complementary to one another to facilitateengagement therebetween for engaging first and second shaft components1217, 1218, respectively, to one another. Further, male connectionmember 1220 may include an adhesive disposed on an outer peripheralsurface thereof (or may be formed from an adhesive material) and/orfemale connection member 1230 may include an adhesive disposed on aninner surface thereof (or may be formed from an adhesive material) tofacilitate engagement therebetween. More specifically, the adhesive mayinclude UV-activated adhesives, heat-activated adhesives,pressure-activated adhesives, gamma ray-activated adhesives, solventadhesives, or other suitable adhesives. Alternatively, temporary weldingmay be used to secure first and second shaft components 1217, 1218,respectively, to one another. A cleaning solution (not shown), removalinstrument (not shown) or any other suitable mechanism may be used fordisengaging the adhered components 1217, 1218.

With reference now to FIG. 13, tube coupling mechanism 1300 is shownconfigured for releasably engaging first and second shaft components1317, 1318, respectively, of shaft 1312 to one another. Tube couplingmechanism 1300 includes one or more magnets 1322, 1324 imbedded within,coupled to, or disposed on first shaft component 1317 and one or moremagnets 1332, 1334 imbedded within, coupled to, or disposed on secondshaft component 1318. Magnets 1322, 1332 are complementarily-shapedrelative to one another and are oriented to define opposite polaritiesat the exposed surfaces thereof. Similarly, magnets 1324, 1334 arecomplementarily-shaped relative to one another and are oriented todefine opposite polarities at the exposed surfaces thereof. Accordingly,upon approximation of shaft components 1317, 1318, magnets 1322, 1332are attracted to one another, and magnets 1324, 1334 are attracted toone another to engage first and second shaft components 1317, 1318,respectively, to one another. Further, as shown in FIG. 13, magnets1322, 1324 and magnets 1332, 1334 are offset relative to one another andare positioned to define a keyed-configuration, thus inhibiting rotationor disengagement of first and second shaft components 1317, 1318,respectively, from one another in response to axial and/or rotationalloading thereof.

Referring now to FIG. 14, another embodiment of a tube couplingmechanism is shown generally identified via reference numeral 1400. Tubecoupling mechanism 1400 is configured to releasably engage first andsecond components 1417, 1418 of shaft 1412 to one another. Morespecifically, tube coupling mechanism 1400 includes a plurality ofcantilever arms 1420 disposed radially about longitudinal axis “A-A” andextending distally from one of the shaft components, e.g., first shaftcomponent 1417, and a plurality of complementary-shaped recesses 1432defined within hub 1430 of the other shaft component, e.g., second shaftcomponent 1418. Similarly as described above with respect to previousembodiments, tabs 1422 extending from cantilever arms 1420 areconfigured for engagement within recesses 1432 of hub 1430 uponapproximation of first and second shaft components 1417, 1418,respectively, to engage first and second shaft components 1417, 1418 toone another.

Turning now to FIG. 15, tube coupling mechanism 1500 is configured toreleasably engage first and second shaft components 1517, 1518,respectively, of shaft 1512 to one another. One of the shaft components,e.g., first shaft component 1517, includes an insertion portion 1520extending from distal end 1522 thereof, while the other shaft component,e.g., second shaft component 1518, includes a receiving portion 1530disposed at proximal end 1532 thereof that is configured to receiveinsertion portion 1520 therein for releasably engaging first and secondshaft component 1517, 1518, respectively, to one another. Further, arelease ring 1540 is disposed on first shaft component 1517 and islongitudinally slidable thereabout to permit disengagement of first andsecond shaft components 1517, 1518, as will be described below.

Continuing with reference to FIG. 15, insertion portion 1520 of firstshaft component 1517 defines a diameter that is slightly smaller than adiameter of lumen 1534 of receiving portion 1530 of second shaftcomponent 1518 to permit insertion of insertion portion 1520 into lumen1534 of receiving portion 1530 and to retain insertion portion 1520 inengagement within receiving portion 1530 via friction-fitting. Further,insertion portion 1520 defines a textured outer peripheral surface 1524configured to facilitate engagement of insertion portion 1520 withinlumen 1534 of receiving portion 1530.

Receiving portion 1530 of second shaft component 1518 defines agenerally cylindrical configuration and is formed from a helically-woundbraid, e.g., a biaxial braid, of material. Due to this braidedconfiguration, receiving portion 1530 is elongated and constricted,i.e., the length of receiving portion 1530 is increased and the diameterof lumen 1534 is reduced, upon axial extension of receiving portion1530. Receiving portion 1530 is normally disposed in an at-restposition, wherein receiving portion 1530 defines a relatively smallerlength and wherein lumen 1534 defines a relatively larger diameter ascompared to the extended position.

In use, in order to engage first and second shaft components 1517, 1518,respectively, to one another, insertion portion 1520 is inserted intolumen 1534 of receiving portion 1530. In this position, textured outerperipheral surface 1524 of insertion portion 1520 facilitates thefrictional engagement of insertion portion 1520 of first shaft component1517 within receiving portion 1530 of second shaft component 1518.Further, removal of insertion portion 1520 from receiving portion 1530is inhibited by the braided-configuration of receiving portion 1530.More specifically, attempted withdrawal of insertion portion 1520 causesaxial extension of receiving portion 1530 which, in turn, constricts, orreduces the diameter of lumen 1534 of receiving portion 1530.Accordingly, receiving portion 1530 is constricted about insertionportion 1520, thereby increasing the frictional engagement therebetweenand inhibiting withdrawal of insertion portion 1520 from receivingportion 1530.

In order to disengage first and second shaft components 1517, 1518,respectively, release ring 1540 is slid distally over first shaftcomponent 1517 into position abutting the proximal end of receivingportion 1530 of second shaft components 1518. Thereafter, whilemaintaining release ring 1540 in position abutting receiving portion1530, first shaft component 1517 is translated proximally relative tosecond shaft component 1518 to withdraw insertion portion 1520 fromreceiving portion 1530, thereby disengaging first and second shaftcomponent 1517, 1518, respectively, from one another. Release ring 1540inhibits extension of receiving portion 1530 during withdrawal of firstshaft component 1517 such that the diameter of lumen 1534 of receivingportion 1530 is maintained. In other words, release ring 1540 inhibitsextension and constriction of receiving portion 1530, thus permittingdisengagement of first and second shaft components 1517, 1518,respectively, from one another.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. While several embodiments of the disclosure have been shownin the drawings, it is not intended that the disclosure be limitedthereto, as it is intended that the disclosure be as broad in scope asthe art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. A surgical instrument, comprising: a shaftdefining a longitudinal axis therethrough and having an end effectorassembly disposed at a distal end thereof, the shaft including first andsecond shaft components that are releasably engageable with one another;a drive sleeve disposed within the shaft and longitudinally translatablerelative to the shaft to transition the end effector assembly between afirst state and a second state, the drive sleeve including first andsecond drive sleeve components that are releasably engageable with oneanother; and a coupling mechanism including: a first cantilever springbiased away from the longitudinal axis of the shaft and configured toengage the first shaft component at a first end thereof and configuredto engage the second shaft component at a second end thereof toreleasably engage the first and second shaft components to one another;and a second cantilever spring biased toward the longitudinal axis ofthe shaft and coupled to the first cantilever spring, the secondcantilever spring configured to engage the first drive sleeve componentat a first end thereof and configured to engage the second drive sleevecomponent at a second end thereof to releasably engage the first andsecond drive sleeve components to one another, wherein the firstcantilever spring and the second cantilever spring are coupled to oneanother via a break-away feature, the break-away feature configured tobreak, decoupling the first cantilever spring and the second cantileverspring from one another to permit the drive sleeve to translate relativeto the shaft.
 2. The surgical instrument according to claim 1, whereinthe second cantilever spring includes a first tab disposed at the firstend thereof and extending therefrom and a second tab disposed at thesecond end thereof and extending thereform, the first tab and secondtabs configured to bias into engagement within apertures defined withinthe first and second drive components, respectively, to engage the firstand second drive sleeve components to one another.
 3. The surgicalinstrument according to claim 1, further comprising: a knife assemblydisposed within the drive sleeve, the knife assembly including a knifebar having a knife disposed at a distal end of the knife bar, the knifebar longitudinally translatable through the shaft and relative to theend effector assembly to translate the knife between a retractedposition and an extended position for cutting tissue.